Lockwood Valveless Pulse Jet Project

Best way to get rid of the flat is to feed it the other way. However with a cone that may not be possible.

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Once the edge clears one of rollers, the middle roller can’t engage and bend the material. For most things, not very noticeable.

He’s doing a good job and gettin er done!

It’s alive! Initial live fire worked. Hearing protection required.

In for weld repair, will do next test in a bit. At WOT (Propane tank inverted injecting liquid) jumped but flame out is occurring need throttle back a bit before blasting liquid in.

Some creative fixturing to use endmill to cut 1/2" hole for fuel rail, it was not very rigid and had a lot of vibration, needed more clamps and large v blocks

Aligning final weld was hardest part, every part is a different diameter so it doesn’t lay flat. CNC cutting a jig to hold all the pieces together would have made it easier, but it turned out ok just sticking random pieces of wood under it until it looked good

Next will need to experiment with venturi / wall between intake and exhaust, theory is that at high thrust the intake is sucking in exhaust gas causing it to extinguish itself


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I think this is the loudest thing I’ve ever heard.

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Good thing we did this around the same time as fireworks and other suspicious noises!

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A pulsejet is basically a fire powered speaker. Just happens to also make thrust.

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Looks like the direction the tank is being rotated as its tipped over when transitioning to liquid could be closing the OPD valve which would explain the abrupt stop. Might have to experiment with flipping technique(plus a completely full tank will help, as buoyancy is needed to keep gravity from closing valve). If it was started upside down it would never trigger the OPD valve until liquid was mostly drained as buoyancy would keep it open.

Got some 3/4" stainless rod to use to change how the fuel rail is attached, will weld this larger rod to combustion chamber, then weld fuel rail to this larger tube. Currently the fuel rail is held in place with two nuts and allows combustion gases to escape. Got a $9 cobalt drillbit and was able to drill it out to 31/64 and then ream to 1/2 with no problem.

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Some I’m gonna double down and again motion that we consider moving this to the members only category… can I get a second?

It’s already there. Lisa said she moved it when she responded to your other post

Ah. Good deal. For some reason I’m just now seeing that. Carry on!

So has anyone done any research to see if this really could get DMS in trouble? I don’t think I have access to the lease to look there, but I looked at the City of Carrollton ordinances last night and I think the only potential problem would be a noise violation if someone complained (which is possible, but unlikely due to the industrial area location and doing this after business hours). There’s a part against operating large combustion engines (boat, plane, etc) between 10pm and 7am wihting 1000 feet of a residential area, but I don’t think DMS meets that criteria.

I understand and appreciate the concern to protect DMS, but also want to point out that these project posts are done to show off what DMS has to offer and inspire people to come participate or do something cool of their own to share :slight_smile: Which hopefully attracts folks who aren’t members yet if they stumble onto Talk!

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Finally got better at making fuel rail on 3rd attempt, and finally realized that 5c collet is much better way to hold the only slightly larger than 1/2" tube than cranking down on the 3 jaw.


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New fuel rail installed

Test fired it some with a needle valve instead of a ball valve for fuel rate control, it was definitely just running way too rich on liquid which would kill it before, have to decrease the throttle to just barely open before flipping to liquid propane and it will still shoot flames out of both ends. It ran steady at 30-40 pounds of thrust for half a minute or so

Soon will have to mount it on something mobile

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Go kart frame? That might be a little fun.

Do the elecric cart. Skip leaf blower - when you reach reach ram air inducton velocity spark it off!

Note; This is a mod of Mitch’s original idea of it being a hybrid.